1. Field of the Invention
The present invention relates to a novel method of administering calcitonin to patients and to formulations adapted for rectal and vaginal administration. More particularly, the present invention relates to calcitonin-containing pharmaceutical formulations containing therein caprylic acid monoglyceride which promotes absorption of calcitonin and thereby enhances its bioavailability.
2. Description of the Prior Art
The method of administration of pharmaceutically active calcitonin is predominantly by injection, although efforts were made in the prior art to use other modes of administration. While administration by injection is acceptable for short-term therapy, administration by injection to patients in need of long-term calcitonin therapy has serious problems. Not only is it costly to patients to have physicians do the administration for extended periods of time, but it is also painful and inconvenient. Nor can calcitonin be given orally to patients since oral administration will result in degradation of calcitonin.
Recently, the prior art has found that calcitonin may also be administered via the rectal route; however, it was also found that certain absorption promoters enhance absorption of calcitonin through the rectal mucosa and as such may be used to advantage in calcitonin suppositories. Absorption promoters that provided increased absorption include certain surface active agents, amino acid derivatives, and certain nonsurfactant adjuvenants, such as, ethylacetoacetate, dimethylethoxymethylenemalonate, sodium salicylate and the like.